When Is Judicial Behavior Political?

The debates about Chief Justice Roberts’s motivations for his health-care opinion rage on with new leaks appearing almost every day. Randy Barnett responds to Jonathan Adler’s attempt at showing that Roberts’s opinion is quite consistent with his past judgments:

But this does not [make] his bending himself into a pretzel to uphold a law when the screws were put to him any less political. [..] 8 justices acted on principle: 4 on good principles and 4 on bad principles.

This probably reflects the majority view among legal scholars, although they differ on precisely which four justices acted on “good principles.” Nonetheless, to imply that this principled behavior is non-political is a bit silly. Indeed, Barnett writes that:

It is hard to imagine Republican politicians citing John Roberts as the type of justice they favor nominating in the future (as many did up until now). Whether or not the decision does lasting damage to the Constitution and the Court, however, itself will depend on how the political process responds. If the electorate proceeds to change the political party of the presidency and the Senate, then this decision could precipitate a turning point in constitutional law, leading to a much more faithful interpretation of the written Constitution.

In other words, the politics is in the selection. If voters elect the "right" party then we get the "right" interpretation of the Constitution. This is consistent with what political scientists call the attitudinal model of judicial behavior.

What differentiates the critique on Roberts is not that his judgment was political but that he acted strategically. His opinion allegedly did not reflect his “principles” nor legal precedent but took account of anticipated responses to his ruling by other actors that could affect Roberts’s long-term goals, such as the legitimacy of the Court, the legitimacy of his own position, or the effect of legal precedent (e.g. the commerce-clause interpretation).

Critics have not, however, been very specific about what these strategic calculations might be. A favorite among conservatives seems to be that Roberts bent to pressure from liberal media and lawmakers. I guess this is what Barnett implies with “when the screws were put to him.” I am not so sure what long-term objective this would serve. If Roberts had gone the other way, most of the pressure would have been on Kennedy rather than on him, given ex ante expectations. In many ways, he could have saved himself a lot of trouble by siding with the conservatives. This makes me think that if his reasoning were indeed motivated by strategic concerns, it probably had something to do with long-term perceptions about the Court rather than his person, especially his views about a more restrained role of the Court. But I am not sure if I have a clear model of this type of behavior. What do you think?